Substituted 4.4&#39; dihydroxybisacylamino-arsenobenzenes



Patented Aug. 14, 1928.

UNITED STATES PATENT OFFICE.-

LOUIS BENDA, 0F MAINKUR, NEAR FRANKFORT-ON-THE-MAIN, GERIN IANY, ASSIGNOR TO I. G. FARBENINDUSTRIE AK'lIEN(:rESELLSCHAIT, A CORPORATION OF GERMANY.

SUBSTITUTED 4.4 DIHYDROXYBISACYLAMINO -AlBSENOBENZENES.

Io Drawing. Application filed May 23, 1927, Serial No. 193,744, and in Germany June 28, 1926.

My present invention relates to new substituted 4.4'-dihydroxybisac l'amino-arsenobenzenes having probably t e general formula:

wherein the Xs mean hydrogen atoms, of which at least one is replaced by a monovalent substituent, which may be obtained by reducing the corresponding arsonic acid compounds by means of reducing agents usual for this process.

The new arscno compounds are distinguished by an excellent resistance to the air (therefore they may be prepared, isolated purified etc. in open vessels with access of air without any change of the products or increase of their toxity, theymay be dispensed per os without any precaution in powder form, in tablets or in aqueous suspension) and by a very good curative power for instance toward syphilis. They are very well endured, also when dispensed per 0s, and in contrast to other arsenical compounds commended for the peroral treatment of syphilis they do not produce injurious by-effects on the nervous system (trembling, excitement, movements, dancing mouses). The new compounds are appropriated also for a peroral treatment of certain tropical diseases.

4.4 dihydroxybisacylamino arsenobenzenes, which contain a chlorine atom in each benzene nucleus, are especially valuable.

In order to further illustrate my invention the following examples are given, the parts being by weight and all temperatures in centig rade degrees, but it is understood, that my invention is not limited to the particular products or reacting conditions mentioned therein.

Ewa/mple I.

parts of the 3-chloro-4-hydroxy-5-acetaminobenzene-l-arsonic acid, described in U. S. Patent 1,588,382, are intimately mixed with 550 parts of methylic alcohol and while well cooling about 150 parts of hydrochloric acid (d=l,185) are added carefully, the temperature not rising above 15. The. somewhat turbid liquor is filtered and while adding parts of hydroiodic acid (Z= 1,7) it is mixed at about 16-17 with a solution prepared as follows:

100 parts of sodium hypophosphite are d ssolved in 50 parts of'boiling water and after cool1ng down the solution there are added 500 parts of methylic alcohol and about 230 parts of hydrochloric acid (d=l,185). Then at about 15 the liquor is filtered from the separated common salt.

The m1xture of the aforesaid components warms by itself to about 24 and the new arseno compound separates slowly as a yellow powder. After about half an hour the precipitate is filtered through an open 7 filter and washed with mcthylic alcohol and T ether. The new compound having probably the formula:

OH OH CHaOONH C1 C1 NHOOCH;

is when dry a yellowish powder, insoluble in water, easily soluble in dilute caustic alkali solutions, difficultly soluble in alcohol. It is precipitated unchanged by acidifying the alkaline solutions. It is not diazotizable.

Ewample I].

CHICONH NHCOGH:

is obtained, which is similar in its proper- 10o ties to the compound, described in Example I, but more soluble in alcohol.

ing probably the general formula:

' on on HUI-NH x X NH-aeyl wherein the Xs mean hydrogen atoms, of which at least one is replaced by a monovalent substituent, which products are when dry yellowish powders, insoluble in water, easily soluble in dilute caustic alkali solutions and precipitated by acidifying these solutions, being not diazotizable, distinguished by an excellent resistance to the air and by a very good curative power.

2. As new products chlorinated 4.4-dig to the aforesaid' hydroxybisacylamino arsenobenzenes having probably the general formula:

on on acyl-NH NH-acyl c1 I B; a which are when dry yellowish wders, insoluble in water, easily solub e in dilute caustic alkali solutions and precipitated by acidifyin these solutions, being not diazotizable, 'stinguished by an excellent resistance to the air and by a very good curative power.

3. As a new product the compound of the r on on omoonrhqm wQqmooom probable formula:

being when dry yellowish wder, insoluble in water, easily soluble in dilute caustic alkali solutions, dlificultl soluble in alcohol 'and not being diazotiza 1e.

In testimony whereof, I aflix my signature.

LOUIS BENDA. 

